The SplintER series is back with a new sub-series – Leg Day! We will review lower extremity orthopedic injuries, introduce advanced concepts, and highlight ways to implement these into your next shift. In this post, we summarize the appropriate way to evaluate, diagnose, and manage tibial plateau fractures. This post is peer-reviewed by Dr. Kori Hudson, one of our expert sports medicine colleagues! Please read below for her commentary.
Learning Objectives
- Understand how to evaluate a suspected tibial plateau fracture
- Understand how and when to utilize the plan radiograph and/or CT scan
- Identify the structures at risk with a tibial plateau fracture
- Recognize radiograph findings of a tibial plateau fracture
- Explain when to consult an orthopedic surgeon
What is the tibial plateau?
The tibial plateau is the weight-bearing surface of the tibia at the knee joint and is important as the knee is a high load-bearing joint. There are several structures within the plateau which are at risk for concomitant injury with a tibial plateau fracture, such as the popliteal artery, peroneal nerve, collateral ligaments, and menisci.
Figure 1. Tibial plateau anatomy (from Wikiradiography)
Who is injured?
With the increase in motor vehicle collisions, males in their 40s to 50s are the most likely to sustain a higher energy trauma.1,2 Elderly patients, more commonly female, make up the majority of lower energy mechanisms, such as a fall.1,3–5 The classic, less common, “bumper injury” occurs when a car’s bumper strikes a pedestrian’s fixed knee with a high-energy valgus force.3–5 The higher energy traumas result in a greater incidence of concurrent soft tissue injuries.
What is injured?
Most tibial plateau fractures (80%) involve the lateral plateau where a valgus stress drives the lateral femoral condyle onto the lateral tibial plateau.6 A varus stress causes the less common medial tibial plateau fracture. One study demonstrated that 97% of patients with acute tibial plateau fractures had concomitant injuries such as collateral ligament and meniscus tears.7
How should I evaluate a suspected tibial plateau fracture?
The initial exam of any injured extremity should be focused first on neurovascular integrity and then bony deformity.
- Arteries: Evaluate for equal dorsalis pedis and/or posterior tibial pulses. Have a high index of suspicion for vascular injuries especially to the popliteal artery.
- Peripheral nerves: The tibial and peroneal nerves are at risk for damage. The tibial (T) nerve runs through the popliteal fossa, and the peroneal (P) nerve runs around the fibula.
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- Motor: Test ankle plantar flexion (T) and dorsiflexion (P)
- Sensation: Check sensation along posterior calf/plantar foot (T) and lateral calf/dorsal foot (P)
- Remember to examine this bilaterally.
- Surface wounds: Evaluate for any wounds suggestive of an open fracture.
- Compartments: Tibial fractures are at high risk for compartment syndrome. Frequent re-evaluation is required to assess for progression of symptoms which may require urgent intervention.
Are plain radiographs good enough?
Plain radiographs of both the knee and the tibia/fibula are commonly obtained when concerned for fracture. The most common radiographs of the knee are anteroposterior (AP) and lateral views. A normal AP film of the tibia and fibula is displayed in Figure 2.7 Intuitively, the sensitivity of injury detection increases the more views obtained; however, the overall sensitivity for fracture detection is cited only around 85% even with 4 views.8 If clinical suspicion still exists for a bony injury, it is reasonable to pursue CT imaging.
Figure 2. Normal AP knee view (from Wikiradiography)
What do I look for on plain radiography?
On the AP view, follow the tibial plateau from lateral to medial.1 It should be smooth without layering, disruption, or depression. Figure 3 demonstrates a lateral plateau fracture. Pay special attention to the ligamentous insertion points such as the lateral tibial condyle which can demonstrate an avulsion fracture or Segond fracture (Figure 4) implying an ACL tear.5 When reviewing a lateral film, look not just for an effusion, but a lipohemarthrosis (Figure 5).7 Lipohemarthrosis is the extravasation of blood and fat from bone marrow into the joint space after a fracture. Depending on the view, lipohemarthrosis might be the only clue to a fracture of the distal femur, tibial plateau, or patella.
Figure 3. Lateral tibial plateau fracture
Figure 4. Segond fracture
Figure 5. Lipohemarthrosis: The arrow points to the radiolucent fat layering above the radiopaque blood. This can be the only indication to a distal femur, tibial plateau, or, less commonly, a patellar fracture. (From James Heilman, MD [CC BY-SA 3.0], from Wikimedia Commons)
When do I get a CT?
If you suspect a vascular insult, a CT angiogram should be obtained immediately to evaluate the integrity of the popliteal artery. If there is clinical concern for fracture, but none is seen on plain radiograph, or if a lipohemarthrosis is seen on plain radiograph, obtain a CT scan without IV contrast will evaluate further for possible occult fracture. Otherwise, discuss with your orthopedic colleagues as they will likely require one for further characterizing the fracture and for operative planning.
Should I consult my orthopedic colleagues?
Yes. However, not all tibial plateau fractures require operative repair. There is a significant morbidity associated with these fractures especially in active and ambulatory patients. Advanced imaging may be required in the outpatient setting to evaluate for ligamentous and cartilaginous injuries which may warrant surgical attention as well. Beyond the concomitant soft tissue injuries, the largest concern is post-traumatic arthritis and early onset osteoarthritis.
Expert Peer Review: Kori Hudson, MD |
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Tibial plateau injuries are serious injuries that require prompt attention and appropriate evaluation to avoid misdiagnosis or significant morbidity. The mechanism of injury should be considered and any injury that includes a direct blow to the knee, proximal leg, or distal thigh should raise suspicion. Fractures may be subtle on the initial plain radiographs, so patients with a concerning mechanism, significant effusion, severe tenderness, or inability to bear weight should have additional imaging with a non-contrast CT. Furthermore, the likelihood of concomitant soft tissue injuries is high enough that patients should be prepared for the fact that they may need additional imaging. The importance of outpatient follow up must be stressed. Finally, don’t forget to assess and reassess neurovascular status. As noted above, there is a risk of vascular injury associated with tibial plateau fractures. Any patient with diminished pulses or a cool extremity on initial exam should have an urgent vascular assessment. Any patient who develops worsening pain, diminished distal pulses, diminished sensation, or swollen hard compartments in the lower leg should have immediate evaluation of compartment pressures, orthopedic consultation, and evaluation for urgent fasciotomy. |
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